<?php
/*
* This is a PHP library that handles calling reCAPTCHA.
*    - Documentation and latest version
*          http://recaptcha.net/plugins/php/
*    - Get a reCAPTCHA API Key
*          https://www.google.com/recaptcha/admin/create
*    - Discussion group
*          http://groups.google.com/group/recaptcha
*
* Copyright (c) 2007 reCAPTCHA -- http://recaptcha.net
* AUTHORS:
*   Mike Crawford
*   Ben Maurer
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/

/**
* The reCAPTCHA server URL's
*/
define("WSD_RECAPTCHA_API_SERVER", "http://www.google.com/recaptcha/api");
define("WSD_RECAPTCHA_API_SECURE_SERVER", "https://www.google.com/recaptcha/api");
define("WSD_RECAPTCHA_VERIFY_SERVER", "www.google.com");

/**
* Encodes the given data into a query string format
* @param $data - array of string elements to be encoded
* @return string - encoded request
*/
function wsd__recaptcha_qsencode ($data) {
		$req = "";
		foreach ( $data as $key => $value )
				$req .= $key . '=' . urlencode( stripslashes($value) ) . '&';

		// Cut the last '&'
		$req=substr($req,0,strlen($req)-1);
		return $req;
}



/**
* Submits an HTTP POST to a reCAPTCHA server
* @param string $host
* @param string $path
* @param array $data
* @param int port
* @return array response
*/
function wsd__recaptcha_http_post($host, $path, $data, $port = 80) {

		$req = wsd__recaptcha_qsencode ($data);

		$http_request  = "POST $path HTTP/1.0\r\n";
		$http_request .= "Host: $host\r\n";
		$http_request .= "Content-Type: application/x-www-form-urlencoded;\r\n";
		$http_request .= "Content-Length: " . strlen($req) . "\r\n";
		$http_request .= "User-Agent: reCAPTCHA/PHP\r\n";
		$http_request .= "\r\n";
		$http_request .= $req;

		$response = '';
		if( false == ( $fs = @fsockopen($host, $port, $errno, $errstr, 10) ) ) {
				die ('Could not open socket');
		}

		fwrite($fs, $http_request);

		while ( !feof($fs) )
				$response .= fgets($fs, 1160); // One TCP-IP packet
		fclose($fs);
		$response = explode("\r\n\r\n", $response, 2);

		return $response;
}



/**
* Gets the challenge HTML (javascript and non-javascript version).
* This is called from the browser, and the resulting reCAPTCHA HTML widget
* is embedded within the HTML form it was called from.
* @param string $pubkey A public key for reCAPTCHA
* @param string $error The error given by reCAPTCHA (optional, default is null)
* @param boolean $use_ssl Should the request be made over ssl? (optional, default is false)

* @return string - The HTML to be embedded in the user's form.
*/
function wsd_recaptcha_get_html ($pubkey, $error = null, $use_ssl = false)
{
	if ($pubkey == null || $pubkey == '') {
		die ('To use reCAPTCHA you must get an API key from <a href="https://www.google.com/recaptcha/admin/create" target="_blank">https://www.google.com/recaptcha/admin/create</a>');
	}

	if ($use_ssl) {
				$server = WSD_RECAPTCHA_API_SECURE_SERVER;
		} else {
				$server = WSD_RECAPTCHA_API_SERVER;
		}

		$errorpart = "";
		if ($error) {
		$errorpart = "&amp;error=" . $error;
		}
		return '<script type="text/javascript" src="'. $server . '/challenge?k=' . $pubkey . $errorpart . '"></script>

	<noscript>
		<iframe src="'. $server . '/noscript?k=' . $pubkey . $errorpart . '" height="300" width="500" frameborder="0"></iframe><br/>
		<textarea name="recaptcha_challenge_field" rows="3" cols="40"></textarea>
		<input type="hidden" name="recaptcha_response_field" value="manual_challenge"/>
	</noscript>';
}




/**
* A wsd_ReCaptchaResponse is returned from wsd_recaptcha_check_answer()
*/
class wsd_ReCaptchaResponse {
		var $is_valid;
		var $error;
}


/**
* Calls an HTTP POST function to verify if the user's guess was correct
* @param string $privkey
* @param string $remoteip
* @param string $challenge
* @param string $response
* @param array $extra_params an array of extra variables to post to the server
* @return wsd_ReCaptchaResponse
*/
function wsd_recaptcha_check_answer ($privkey, $remoteip, $challenge, $response, $extra_params = array())
{
	if ($privkey == null || $privkey == '') {
		die ('To use reCAPTCHA you must get an API key from <a href="https://www.google.com/recaptcha/admin/create" target="_blank">https://www.google.com/recaptcha/admin/create</a>');
	}

	if ($remoteip == null || $remoteip == '') {
		die ('For security reasons, you must pass the remote ip to reCAPTCHA');
	}



		//discard spam submissions
		if ($challenge == null || strlen($challenge) == 0 || $response == null || strlen($response) == 0) {
				$recaptcha_response = new wsd_ReCaptchaResponse();
				$recaptcha_response->is_valid = false;
				$recaptcha_response->error = 'incorrect-captcha-sol';
				return $recaptcha_response;
		}

		$response = wsd__recaptcha_http_post (WSD_RECAPTCHA_VERIFY_SERVER, "/recaptcha/api/verify",
										array (
												'privatekey' => $privkey,
												'remoteip' => $remoteip,
												'challenge' => $challenge,
												'response' => $response
												) + $extra_params
										);

		$answers = explode ("\n", $response [1]);
		$recaptcha_response = new wsd_ReCaptchaResponse();

		if (trim ($answers [0]) == 'true') {
				$recaptcha_response->is_valid = true;
		}
		else {
				$recaptcha_response->is_valid = false;
				$recaptcha_response->error = $answers [1];
		}
		return $recaptcha_response;

}

/**
* gets a URL where the user can sign up for reCAPTCHA. If your application
* has a configuration page where you enter a key, you should provide a link
* using this function.
* @param string $domain The domain where the page is hosted
* @param string $appname The name of your application
*/
function wsd_recaptcha_get_signup_url ($domain = null, $appname = null) {
	return 'https://www.google.com/recaptcha/admin/create?' .  wsd__recaptcha_qsencode (array ('domains' => $domain, 'app' => $appname));
}

function wsd__recaptcha_aes_pad($val) {
	$block_size = 16;
	$numpad = $block_size - (strlen ($val) % $block_size);
	return str_pad($val, strlen ($val) + $numpad, chr($numpad));
}

/* Mailhide related code */

function wsd__recaptcha_aes_encrypt($val,$ky) {
	if (! function_exists ("mcrypt_encrypt")) {
		die ('To use reCAPTCHA Mailhide, you need to have the mcrypt php module installed.');
	}
	$mode=MCRYPT_MODE_CBC;
	$enc=MCRYPT_RIJNDAEL_128;
	$val=wsd__recaptcha_aes_pad($val);
	return mcrypt_encrypt($enc, $ky, $val, $mode, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");
}


function wsd__wsd_recaptcha_mailhide_urlbase64 ($x) {
	return strtr(base64_encode ($x), '+/', '-_');
}

/* gets the reCAPTCHA Mailhide url for a given email, public key and private key */
function wsd_recaptcha_mailhide_url($pubkey, $privkey, $email) {
	if ($pubkey == '' || $pubkey == null || $privkey == "" || $privkey == null) {
		die ('To use reCAPTCHA Mailhide, you have to sign up for a public and private key, ' .
			'you can do so at <a href="http://www.google.com/recaptcha/mailhide/apikey" target="_blank">http://www.google.com/recaptcha/mailhide/apikey</a>');
	}


	$ky = pack('H*', $privkey);
	$cryptmail = wsd__recaptcha_aes_encrypt ($email, $ky);

	return "http://www.google.com/recaptcha/mailhide/d?k=" . $pubkey . "&c=" . wsd__wsd_recaptcha_mailhide_urlbase64 ($cryptmail);
}

/**
* gets the parts of the email to expose to the user.
* eg, given johndoe@example,com return ["john", "example.com"].
* the email is then displayed as john...@example.com
*/
function wsd__recaptcha_mailhide_email_parts ($email) {
	$arr = preg_split("/@/", $email );

	if (strlen ($arr[0]) <= 4) {
		$arr[0] = substr ($arr[0], 0, 1);
	} else if (strlen ($arr[0]) <= 6) {
		$arr[0] = substr ($arr[0], 0, 3);
	} else {
		$arr[0] = substr ($arr[0], 0, 4);
	}
	return $arr;
}

/**
* Gets html to display an email address given a public an private key.
* to get a key, go to:
*
* http://www.google.com/recaptcha/mailhide/apikey
*/
function wsd_recaptcha_mailhide_html($pubkey, $privkey, $email) {
	$emailparts = wsd__recaptcha_mailhide_email_parts ($email);
	$url = wsd_recaptcha_mailhide_url ($pubkey, $privkey, $email);

	return htmlentities($emailparts[0]) . "<a href='" . htmlentities ($url) .
		"' onclick=\"window.open('" . htmlentities ($url) . "', '', 'toolbar=0,scrollbars=0,location=0,statusbar=0,menubar=0,resizable=0,width=500,height=300'); return false;\" title=\"Reveal this e-mail address\">...</a>@" . htmlentities ($emailparts [1]);

}


?>
